This invention relates to electrical connections and more particularly to a device for mechanically and electrically protecting the ends of two or more electrical conductors which have been joined together to form an electrical connection.
In the joining of electrical conductors, the mechanical and electrical protection of the united ends of the conductors is a major concern, particularly when the joined conductors are to be exposed to harsh environments, such as by being buried in the ground or being exposed to the elements. Various protective devices for insulating and mechanically protecting the joined electrical conductors have been known for a number of years, and by way of example, several general forms of such devices can be found in U.S. Pat. Nos. 997,066, 1,297,614, and 3,597,528.
Devices of the general type shown in the foregoing patents and of the general type to which the present invention relates, comprise a generally tubular member or casing having a side wall, a closed end wall, and an open end, and a second member or plug adapted to mate with the tubular casing an close off the open end of the casing. Passages are provided in either the end wall of the casing or that of the plug to permit the conductors to extend therethrough. To bond the casing and plug together, bonding and insulating compound or adhesive is disposed within the device and which substantially fills the interior of the device to anchor or bond the conductors therein and provide further electrically insulation for the joined conductors.
While such devices have had many desirable features, the problem of providing a good and reliable weather tight seal has not heretofore been satisfactorily solved. One major problem resides in the flow of the uncured bonding or potting compound, which is typically liquid in form, around the conductors and through the end wall passages during assembly of the plug and casing. This results in a wakened bond between the conductor and the passage walls, and also may result in voids or openings through which moisture may enter the device and short out the electrical circuit formed by the connection between the conductors.
A second problem resides in the possibility of a separation of the plug from the casing after assembly and which may result from internal pressures created by assembly of the plug and casing and by the evolution of gases during curing of the potting compound. If the plug separates appreciably from the casing, an effective bonding of the casing and plug will not result and a leak path to the interior of the device through which moisture may travel may be produced.